Inertially armed fuze



March 10, 1964 P. KAISER ETAL 3,124,074

INERTIALLY ARMED FUZE Filed Oct. 13, 1960 5 Sheets-Sheet 1 ffy INVENToRs I Paz/2 Waalse/- vwsef M'ZZefm ,6% ,l/Mza ma ZLys.

March 1o, 1964 Filed OCT.. 15, 1960 Fig.2

P. KAISER ETAL INERTIALLY ARMED FUZE 3 Sheets-Sheet 2 Pau 2 INVENTORJ /1 a wel f BY @Jef Ml'jggef- March 10, 1964 P. KAISER ETAL 3,124,074

INERTIALLY ARMED FUZE:

Filed Oct. 15, 1960 5 Sheets-Sheet 3 Fly. 3

INVENToRs Pau Z /fzdsefldld Patented Mar. l0, 1964 hee 3,l24,ll74 ENERTIALLY ARMED FUE Paul Kaiser, Weihergasse 2S, Schramberg, Wurttemberg,

Germany, and Eosef Mller, Unotweg 6, Schramberg- Sulgen, Wurttemberg, Germany Filed Get. 13, 1960, Ser. No. 62,456 Claims priority, appiication Germany (Bet. 16, 1959 3 Claims. (Cl. 162-73) The invention relates to time fuzes with sensitive percussion fuzing for projectiles, with and without rifiing. It is an object of the invention to equip such a fuze with safety devices which are reliable in transport and also as regards timing. ri`he invention is characterised by a cylindrical worm which is rotatably mounted on the striker pin and which is driven by an inertia weight which is non-rotatably guided in the fuze housing and is procided with transverse pins engaging in the worm groove, the said inertia weight carrying an axially parallel locking member which secures the balance-type regulator of a timing mechanism. In the preferred embodiment of the invention, a toothed wheel is arranged on the cylindrical worm so as to rotate therewith, the said Wheel driving a balance or escapement wheel which co-operates with a rocking pallet which is mounted at the forward end of the Worm. For further locking effect, a known rocker plate which closes the striker pin passage can be mounted behind the worm, the said rocker plate being held against the action of its torsion spring in the safe closed position by a stop pin, which bears externally against the hollow end of the worm, the wall of the hollow end also being formed with a recess for the passage of the stop pin on the rocker plate in the rear dead-centre position of the inertia weight when the worm has completed its rotation.

The allotment of a double safety function to the safety timing mechanism and a construction of its gearing with a cylindrical worm element contributes to a compact, simple and reliable construction.

Other features and advantages of the invention will be apparent from the following description of one constructional example, and from the drawing and claims.

In the drawing:

FIG. l is a longitudinal section of the fuze, including its housing;

FIG. 2 is a longitudinal section of the timing mechanism and of the safety time mechanism, shown to a larger scale as compared with FIG. l;

FiG. 3 is a sectional View on the line 2?*3 of FIG. 2;

FIG. 4 is a sectional View on the line d--l of FIG. 2;

FIG. 5 is a sectional view on the line 5-5 of FlG. 2 with the blocking plate of the striker pin passage in the safe position;

P lG. 6 is a section corresponding to FIG. 5, but with the blocking plate of the striker pin passage in the end safe position.

ln order that the sensitive fuzing and also the time fuzing of the fuze illustrated may be made safe, there is provided a time safety mechanism which adjoins the bottom plate 58 of the timing mechanism (FIG. 2). The reference 10i) represents the top plate of the time-safety mechanism, lill is an intermediate plate, im is a cover plate, while li3 is an additional intermediate plate and hifi is the bottom plate. Some of these mechanism plates are held assembled by screws and some are held in spaced relation by posts 165, 1M. Rotatably mounted between the plates itil and liiZ is the cylindrical worm member 167; it comprises a worm thread lit'a which has a steep pitch and which is engaged by a pin 163 xed radially in an inertia weight 169. The latter is guided axially on the posts 165 and 196 (FIGS. 2 and 4). The toothed wheel llt) is rotatably mounted near the forward end of the worn element 1%7 and it meshes, as shown in FlG. l, with the pinion lll of an escapement wheel 112 which cooperates with the rocking pallet H3, which is pivotally mounted on the striker pin stem 15b as a pivot. The coiled sprin.Q il@ is fitted with pretension between the inertia weight 169 and the cover plate 162. Fitted into the Weight it?? parallel to the fuze axis is the locking iinger Elfi, which extends through suitable holes in the plates itil, Mtl, 53, 57, S6, 55, S4, 53 and 52 and has the object to secure the balance -type regulator 68 of the timing mechanism until the predetermined time-safety travel has been completed and above all also to make it safe against the action of shocks during transport. The forward end of the safety finger 114 is reduced at 114m to a smaller diameter, as shown in FIG. l, so that by means of a hairpin spring 115 pretensioned for expansion and fitted between the plates 58 and im), the safety locking finger ld and with it the inertia weight 109 are held in the (rear) armed position when the time-safety mechanism has completed its service as a safety device. The purpose and function of the timing mechanism 6d is to provide for a balance regulation and it operates in such a way that the regulator 63 is locked until ring takes place by a locking projection projecting into its range of oscillation, as shown immediately to the right of the element 68.

The stern of the safety nger lld is made sufiiciently long, as is also the length of travel for the inertia weight N19 and the timing for the delay mechanism (li'a/ 1%/ 10/ ill/ ilZ/ M3), that with brief shocks during transport, the reduced part lien of the safety finger le still does not come into the range of the locking spring 11S, but in fact the inertia weight and with it the safety finger its again return to the initial locking position after the shock has subsided. The balance mechanism of the timing mechanism thus remains locked, so that the said mechcannot be started as a result of a shock during transport. Furthermore, the safety arrangement still to be described for the blocking plate on the worm member MP7 for the needle passage is so arranged that it is still not released by a brief rotation of the worm member 197 caused by a shock during transport. The time-safety mechanism is in other words adapted to the ballistic property of the rocket projectile, that is to say, to the low tiring pressure and to the fact that the maximum acceleration is only reached after about 0.5 to 0.8 second. The arming of the timing mechanism must take place in a reliable manner, but on the other hand the fuze must be safe during transport and on firing. The running period of the time-safety mechanism is arranged accordingly.

ln the example illustrated, the cylindrical worm member N7 completes approximately three quarters of a revolution from the starting position at the front to the end position, which is the armed position.

The cylindrical Worm element ltl is reduced at its rear end at itl'b to a smaller diameter and is guided with the said extension piece in the cover plate 192, which simultaneously serves as an axial bearing therefor. The worm element 137 is drilled axially at liV/c, so that a collar ii'b is formed, which is cut away at 19T/d, as shown in FGS. 2, 5 and 6, so that a safety pin 116, which is arranged on the blocking plate 117 for the needle passage and bears during the safe period against the collar M5715 (FlG. 5) but is allowed to pass during the safe period (FlG. 6) when the inertia weight MP9 has reached its rearward position (resting on the cover plate 1h21), whereby the safety finger 114 is locked at 1Mo with the hairpin spring M5 and the worm element 167 has reached the armed position in which the cut-away part 1675i of the collar 10719 lies in the range of movement of the safety pin lid. Acting on the blocking plate H7 is the spring 118 which is installed with pretension and which tends to rotate the plate 117 in a clockwise direction, as indictaed in FlGS. 5 and 6. ln order to avoid the pointed end of the striker pin section b resting on the said member 117 and obstructing the operation thereof, a compression spring 119 is fitted with suitable pretension in the hollow shaft 16 of the spring barrel, the said spring 119 engaging on the rear face of the enlargement 15a of the striker pin.

The operation of the fuze will now be described:

Safety during transport-Should the fuze or the projectile provided with'the fuze drop on to its nose during handling, the striker pin 15 will certainly be driven inwardly by the plate 16 with destruction of the diaphragm 17; the pointed end of the said pin, however, strikes against the blocking plate 117 for the striker pin passage, the said plate being in the safe position (FIG. 5). Since the forces of inertia operative in this case are unidirectional with the force of the thrust spring 119 behind the inertia weight 169, no movement of these parts occurs in practice.

On the other hand, should the projectile drop lon to its base, only comparatively small mass forces act on the striker pin, and these are damped by the spring 119 and generally do not lead to any damage because of upsetting of the striker pin 15b on the blocking plate 117.

However, when the projectile is dropped in this direction, mass forces are operative on the inertial weight 109, Which can cause the weight to slide back a small distance relatively to the spring 119 and initiate the movement for a brief instant of time of the worm element 107, toothed wheel 110, pinion 111, regulator wheel 112 and the rocking pallet 113. However, the parts are of such dimensions that an impact due to dropping is not in any way operative for such a length of time as is necessary to cause the inertia weight 1%'19 to bear on the cover plate 192, since the rearward movement of the said weight is in fact retarded by the pallet 113. As mentioned above, the maximum acceleration with rocket projectiles is only reached after about 0.5 to 0.8 second; this slow increase in speed is thus fundamentally different from the sudden acceleration impulse of an impact due to dropping. Thus, when the projectile is dropped on to its base, the inertia Weight is only moved back a comparatively short distance and is then brought again by the spring 119 into its forward position (FIGS. 1 and 2). The delay mechanism 116, 111, 112, 113 is adjusted for forward and rearward movement. As described above, the stem 114 of the safety finger is held in the inertia weight 109 for the timing escapement 63 until the return movement of the weight 109 into an intermediate position can still not lead to the locking of the finger 114 on the hairpin spring 11S, that is to say, for releasing the balance member 68. Thus, after the shock due to dropping has subsided, all functional parts of the fuze are again in the initial position and all safety devices are fully operative again.

On tiring, the inertia weight 109 is forced rearwardly during the acceleration period and, since it is guided rectilinearly on the posts 105 and 106, the engagement of its pin 168 in the worm 10751 causes a rotation of the worm member 107, which is slowed down by the time of the delay mechanism 110, 111, 112, 113. The rearward movement of the inertia weight 109 is also counteracted by the thrust spring 119. The time-safety mechanism is so adjusted that the bottom surface of the inertia weight 169 has reached the intermediate plate 102 at the end of the l predetermined safety travel. ln this position, the reduced end 11de: of the safety iinger 114 is also at the height of the hairpin locking spring 115, so that the arms thereof close around 114e and it prevents the safety linger 114, and with it the inertia weight 109, from moving forward again under the action of the thrust spring 109 after the rearward pressure has ceased.

The blocking plate 117 for the needle passage now no longer forms an obstacle for the striker pin 15b, since with the rearward travel of the inertia weight 199, the collar 1.37!) arranged on the rear end of the cylindrical worm element 107 has been rotated to such an extent that its cut-away part 1G75! (FIGS. 5 and 6) can now move past the lockingpin 116 on the locking plate 117, which formerly had rested laterally on the collar 167i: (see FIG. 6), so that the passage for the striker pin 15b is freed.

The collar 10711 is also of such dimensions in the peripheral direction that the pin 116 is still not freed in intermediate positions of the worm and of the inertia weight.

We claim:

l. Time fuze with sensitive fuzing for projectiles with and without riding, comprising a striker pin, a cylindrical worm with a spiral groove therein rotatably mounted on the striker pin, an inertia weight provided around the worm to drive the latter, a transverse pin in the weight projecting into and engaging in the groove in the worm, a timing mechanism having a balance regulator mounted in the fuze, means to prevent rotation of the weight, and a safety finger engaging the balance regulator and mounted on the weight parallel to a longitudinal axis of the fuze to secure the balance regulator of the timing mechanism.

2. Time fuze according to claim 1, in which a toothed wheel is provided secured on the cylindrical worm to rotate therewith and in which a pinion and a rocking pallet are provided with the pinion mounted at the forward end of the worm and in cooperative meshing engagement with the toothed wheel to operate the pallet.

3. Time fuze according to claim 1, in which a rocker plate is provided pivotally mounted in a transverse plane in the fuze to one side of the striker pin for shutting oif a passage Jfor the striker pin and is mounted beneath the Worm and the striker pin to serve as an additional safety device and in which a torsion spring and stop pin are provided mounted on the rocker plate, said plate being held against the torsion spring in a safety closed position by the stop pin which bears externally against a hollow end ot the worm, and a wall of the hollow end being formed with a recess therein for the passage of the stop pin on the rocker plate upon completion of the rotation of the worm in the rear dead-centre position of the inertia weight.

References Cited in the le of this patent UNITED STATES PATENTS 969,497 Schneider Sept. 6, 1910 2,149,470 Schenk Mar. 7, 1939 2,164,115 Lasserre June 27, 1939 2,850,979 Hardwick Sept. 9, 1958 2,895,419 Rosselet July 21, 1959 FOREIGN PATENTS 637,152 Great Britain May 17, 1950 

1. TIME FUZE WITH SENSITIVE FUZING FOR PROJECTILES WITH AND WITHOUT RIFLING, COMPRISING A STRIKER PIN, A CYLINDRICAL WORM WITH A SPIRAL GROOVE THEREIN ROTATABLY MOUNTED ON THE STRIKER PIN, AN INERTIA WEIGHT PROVIDED AROUND THE WORM TO DRIVE THE LATTER, A TRANSVERSE PIN IN THE WEIGHT PROJECTING INTO AND ENGAGING IN THE GROOVE IN THE WORM, A TIMING MECHANISM HAVING A BALANCE REGULATOR MOUNTED IN THE FUZE, MEANS TO PREVENT ROTATION OF THE WEIGHT, AND A SAFETY FINGER ENGAGING THE BALANCE REGULATOR AND MOUNTED ON THE WEIGHT PARALLEL TO A LONGITUDINAL AXIS OF THE FUZE TO SECURE THE BALANCE REGULATOR OF THE TIMING MECHANISM. 